Since their discovery in 1991, carbon nanotubes (CNTs) have attracted considerable attention from researchers because of their unique electrical, mechanical, and thermal properties. The remarkable electrical properties of carbon nanotubes make them ideal candidates for applications such as sensors, interconnects, transistors, and flat panel displays. These properties provide an opportunity to develop high performance flexible, transparent electrodes for use in various products. However, for successful implementation into products such as flexible electronics, it is desirable to have methods to deposit and pattern carbon nanotubes over large areas, at high resolution, and with processing temperatures that are compatible with plastics. In order to take advantage of the potential electrical and optical properties of carbon nanotubes, manufacturers will have to be able to pattern the materials into common electronic circuitry forms.
Inkjet printing of carbon nanotubes directly onto a substrate in a desired pattern has been previously proposed. However, such a process has the disadvantages of ink formulation for the carbon nanotubes, resolution limitations, and insufficient attachment to the substrates. Patterning techniques based on substrate and carbon nanotube chemistry interactions have also been previously proposed. This process has the disadvantages of very complicated chemical science, inconsistent results for pattern fill, and the need to pattern the attach chemical prior to attaching the carbon nanotubes. Photolithographic processes have also been proposed. Such processes have the disadvantage of requiring several photolithographic and plasma etch steps to complete the desired pattern. Another proposal is to use laser trimming of carbon nanotubes using a copper mask system. This laser trimming method can produce patterns of carbon nanotubes defined by the copper grid mask. This method has the disadvantages that only patterns defined by the copper grid can be produced, and the laser exposure needs to be uniform over the area being patterned.